The present invention relates to a peelable block comprising a stack of sheets, each one of a predetermined thickness.
In many mechanisms requiring accurate adjustments, it is known to use peelable blocks so as to compensate for the manufacturing tolerances. These blocks provide correct positioning for the elements of the mechanism with respect to each other.
Such peelable blocks comprise a stack of sheets of predetermined thickness bonded to each other. So that the block fits exactly in the gap having to be filled, the elementary sheets forming the block are removed one by one until the overall thickness desired for the block is obtained.
The use of such blocks avoids machining and grinding blocks having a solid metal thickness.
These blocks are used especially in transmission members, gearboxes, bearings and reduction gears.
It is known to provide, depending on the thickness of the block, a first group of sheets having a first thickness then a second group of sheets having a second thickness in order to reduce the cost of the peelable blocks. These thicknesses are, for example, equal to 0.1 mm and 0.05 mm.
When the blocks consist of metal sheets, the sheets of different thicknesses are generally made from different materials. Thus the colours of the sheets are different.
The operator in charge of adjusting the thickness of the block may easily determine, from the colour of the sheets or from their surface state, the number and type of sheets having to be removed in order to obtain the desired thickness.
On the other hand, when the block consists of sheets made of a polymer, the sheets of different thicknesses are generally made from the same material, such that they have the same colour.
It is thus extremely difficult for the operator to differentiate the sheets according to their thickness when adjusting the block.
The polymer sheets may be coloured according to their thickness. However, the colour of the sheets is the underlying cause of an additional cost, during manufacture of the block.
The aim of the invention is to provide a low-cost peelable block allowing the identification of the sheets capable of being removed.
To this end, the subject of the invention is a peelable block of the aforementioned type, characterized in that the said stack of sheets comprises at least one group of transparent successive sheets, and in that the said stack of sheets comprises an identification sheet on which at least one distinctive sign is formed, arranged so as to be visible through a group of successive transparent sheets.
According to particular embodiments, the block comprises one or more of the following characteristics:
it comprises a single identification sheet;
the identification sheet is opaque;
the sheets of any one group all have the same thickness;
the identification sheet has the same thickness as the sheets of a group of sheets;
it comprises a first and a second group of sheets, the sheets of which have a first and a second thickness, respectively, the first and second groups of sheets being arranged on either side of the identification sheet, which identification sheet comprises at least one distinctive sign arranged so as to be visible through only one group of sheets;
the identification sheet comprises two different distinctive signs, one visible only through the first group of sheets and the other visible only through the second group of sheets;
it comprises two identification sheets interposed between the two groups of sheets, each identification sheet comprising at least one distinctive sign arranged so as to be visible only through an associated group of sheets;
the said sheets are made of a polymer;
the identification sheet comprises additional marks which are visible through at least one group of sheets;
it comprises a rigid blank having a thickness greater than the thickness of the sheets or of each group of sheets, which blank is included in the stack of sheets; and
the said blank forms the said identification sheet.